Core support for five years is requested for the competitive renewal of the Kansas University Mental Retardation and Developmental Disabilities Research Center (MRDDRC). The Kansas MRDDRC, now in its 34th year, has played a major role in generating effective interventions aimed at the causes, prevention, and treatment of mental retardation, and in delineating basic knowledge of the underlying biology of typical and atypical development. Building on this rich history, a unique contribution of the Center in the future will be the development of biologically informed behavioral and pharmacological intervention and treatment approaches. Within the context of this biobehavioral direction, the mission of the Kansas MRDDRC is to support high quality basic and applied research relevant to the causes and prevention of mental retardation and the prevention and remediation of secondary conditions associated with mental retardation and related developmental disabilities. To achieve this mission, the Kansas MRDDRC is designed to accomplish three objectives. First, to provide cost effective, state of the art core services, resources, and facilities that directly enhance the quality of science produced by projects associated with the Center. Second, to provide efficient, cost-effective systems for planning, developing, managing, coordinating, and disseminating research activities associated with the center. Third, to develop and support new interdisciplinary basic and applied research initiatives directly relevant to the center's mission among center investigators, and between center investigators and investigators at other research centers throughout the United States and the World. The Kansas MRDDRC's research program is organized around four thematic areas that reflect the scientific directions and strengths of our current efforts. These themes are: 1) language, communication disorders, and cognition of mental retardation; 2) risk, prevention, and intervention in mental retardation; 3) neurobiology of mental retardation; 4) cellular and molecular biology of early development. To coordinate and support the research activities of the 66 investigators and 72 research projects associated with these themes, five core units are proposed: a) Administrative Services and Communication; b) Biobehavioral Measurement; c) Research Design and Analysis; d) Biobehavioral Imaging and Graphics; c) Tissue Culture and Monoclonal Antibodies.